1
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Jiang JJ, Zhao YJ, Guo Y, Gao L, Richards CL, Siemann E, Wu J, Li B, Ju RT. Restoration of native saltmarshes can reverse arthropod assemblages and trophic interactions changed by a plant invasion. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2740. [PMID: 36102220 DOI: 10.1002/eap.2740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/24/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
Plant invasions profoundly impact both natural and managed ecosystems, and removal of the invasive plants addresses only part of the problem of restoring impacted areas. The rehabilitation of diverse communities and their ecosystem functions following removal of invasive plants is an important goal of ecological restoration. Arthropod assemblages and trophic interactions are important indicators of the success of restoration, but they have largely been overlooked in saltmarshes. We determined how arthropod assemblages and trophic interactions changed with the invasion of the exotic plant Spartina alterniflora and with the restoration of the native plant Phragmites australis following Spartina removal in a Chinese saltmarsh. We investigated multiple biotic and abiotic variables to gain insight into the factors underlying the changes in arthropod assemblages and trophic structure. We found that although Spartina invasion had changed arthropod diversity, community structure, feeding-guild composition, and the diets of arthropod natural enemies in the saltmarsh, these changes could be reversed by the restoration of native Phragmites vegetation following removal of the invader. The variation in arthropod assemblages and trophic structure were critically associated with four biotic and abiotic variables (aboveground biomass, plant density, leaf N, and soil salinity). Our findings demonstrate the positive effects of controlling invasive plants on biodiversity and nutrient cycling and provide a foundation for assessing the efficacy of ecological restoration projects in saltmarshes.
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Affiliation(s)
- Jia-Jia Jiang
- National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-Chongming, Fudan University, Shanghai, China
| | - Yu-Jie Zhao
- National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-Chongming, Fudan University, Shanghai, China
| | - Yaolin Guo
- National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-Chongming, Fudan University, Shanghai, China
| | - Lei Gao
- Shanghai Academy of Landscape Architecture Science and Planning, Shanghai, China
| | - Christina L Richards
- Plant Evolutionary Ecology, Institute of Evolution and Ecology, University of Tübingen, Tübingen, Germany
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Evan Siemann
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Jihua Wu
- National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-Chongming, Fudan University, Shanghai, China
| | - Bo Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, Yunnan University, Chenggong, Kunming, Yunnan, China
| | - Rui-Ting Ju
- National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Eco-Chongming, Fudan University, Shanghai, China
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2
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Robertson SM, Schmid RB, Lundgren JG. Estimating plant biomass in agroecosystems using a drop-plate meter. PeerJ 2023; 11:e15740. [PMID: 37547713 PMCID: PMC10404029 DOI: 10.7717/peerj.15740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 06/20/2023] [Indexed: 08/08/2023] Open
Abstract
Reason for doing the work Plant biomass is a commonly used metric to assess agricultural health and productivity. Removing plant material is the most accurate method to estimate plant biomass, but this approach is time consuming, labor intensive, and destructive. Previous attempts to use indirect methods to estimate plant biomass have been limited in breadth and/or have added complexity in data collection and/or modeling. A cost-effective, quick, accurate, and easy to use and understand approach is desirable for use by scientists and growers. Objectives An indirect method for estimating plant biomass using a drop-plate meter was explored for use in broad array of crop systems. Methods Drop-plate data collected by more than 20 individuals from 16 crop types on 312 farms across 15 states were used to generate models to estimate plant biomass among and within crop types. Results A linear model using data from all crop types explained approximately 67% of the variation in plant biomass overall. This model performed differently among crop types and stand heights, which was owed to differences among sample sizes and farming between annual and perennial systems. Comparatively, the model using the combined dataset explained more variance in biomass than models generated with commodity specific data, with the exception of wheat. Conclusions The drop-plate approach described here was inexpensive, quick, simple, and easy to interpret, and the model generated was robust to error and accurate across multiple crop types. The methods met all expectations for a broad-use approach to estimating plant biomass and are recommended for use across all agroecosystems included in this study. While it may be useful in crops beyond those included, validation is suggested before application.
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3
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Beck M, Billoir E, Floury M, Usseglio-Polatera P, Danger M. A 34-year survey under phosphorus decline and warming: Consequences on stoichiometry and functional trait composition of freshwater macroinvertebrate communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159786. [PMID: 36377090 DOI: 10.1016/j.scitotenv.2022.159786] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Worldwide, freshwater systems are subjected to increasing temperatures and nutrient changes. Under phosphorus and nitrogen enrichment consumer communities are often thought to shift towards fast-growing and P-rich taxa, supporting the well-known link between growth rate and body stoichiometry. While these traits are also favoured under warming, the temperature effect on stoichiometry is less clear. As recently shown, there is a general link between functional traits and body stoichiometry, which makes the integration of stoichiometric traits a promising tool to help understanding the mechanisms behind taxonomic and functional community responses to nutrient changes and/or warming. Yet, such approaches have been scarcely developed at community level and on a long-term perspective. In this study, we investigated long-term responses in stoichiometry and functional trait composition of macroinvertebrate communities to nutrient changes (decreasing water P; increasing water N:P) and warming over a 34-year period in the Middle Loire River (France), testing the potentially opposing responses to these drivers. Both drivers should cause shifts in species composition, which will alter the overall community stoichiometry and functional composition following assumptions from ecological stoichiometry theory. We found that the macroinvertebrate community shifted towards P-poor taxa, causing significant trends in overall community stoichiometry which indicates long-term changes in the nutrient pool provided by these consumers (i.e. decrease in %N and %P, increase in N:P). Further, while the former high-P conditions favoured traits associated to detritus feeding and fast development (i.e. small maximum body size, short life duration), recent conditions favoured predators and slow-developing taxa. These results suggest nutrients to be a more important driver than temperature over this period. By providing a pivotal link between environmental changes and functional trait composition of communities, approaches based on stoichiometric traits offer sound perspectives to investigate ecological relationships between multiple drivers operating at various scales and ecosystem functioning.
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Affiliation(s)
| | | | - Mathieu Floury
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, F- 69622, Villeurbanne, France
| | | | - Michael Danger
- LIEC, Université de Lorraine, France; Institut Universitaire de France, Paris, France
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4
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Peng D, Montelongo DC, Wu L, Armitage AR, Kominoski JS, Pennings SC. A hurricane alters the relationship between mangrove cover and marine subsidies. Ecology 2022; 103:e3662. [PMID: 35157321 DOI: 10.1002/ecy.3662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/19/2021] [Accepted: 12/09/2021] [Indexed: 11/11/2022]
Abstract
As global change alters the composition and productivity of ecosystems, the importance of subsidies from one habitat to another may change. We experimentally manipulated black mangrove (Avicennia germinans) cover in ten large plots and over five years (2014-2019) quantifying the effects of mangrove cover on subsidies of floating organic material (wrack) into coastal wetlands. As mangrove cover increased from zero to 100%, wrack cover and thickness decreased by ~60%, the distance that wrack penetrated into the plots decreased by ~70%, and the percentage of the wrack trapped in the first six m of the plot tripled. These patterns observed during four "normal" years disappeared in a fifth year following Hurricane Harvey (2017), when large quantities of wrack were pushed far into the interior of all the plots, regardless of mangrove cover. Prior to the storm, the abundance of animals collected in grab samples increased with wrack biomass. Wrack composition did not affect animal abundance or composition. Experimental outplants of two types of wrack (red algae and seagrass) revealed that animal abundance and species composition varied between the fringe and interior of the plots, and between microhabitats dominated by salt marsh versus mangrove vegetation. The importance of wrack to overall carbon stocks varied as a function of autochthonous productivity: wrack inputs (per m2 ) based on survey data were greater than aboveground plant biomass in the plots (42 × 24 m) dominated by salt marsh vegetation, but decreased to 5% of total aboveground biomass in plots dominated by mangroves. Our results illustrate that increasing mangrove cover decreases the relative importance of marine subsidies into the intertidal at the plot level, but concentrates subsidies at the front edge of the mangrove stand. Storms, however, may temporarily override mangrove attenuation of wrack inputs. Our results highlight the importance of understanding how changes in plant species composition due to global change will impact marine subsidies and exchanges among ecosystems, and foster a broader understanding of the functional interdependence of adjacent habitats within coastal ecosystems.
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Affiliation(s)
- Dan Peng
- Department of Biology and Biochemistry, University of Houston, Texas, USA.,Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Denise C Montelongo
- Department of Biology and Biochemistry, University of Houston, Texas, USA.,Current address: Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Leslie Wu
- Department of Biology and Biochemistry, University of Houston, Texas, USA
| | - Anna R Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, USA
| | - John S Kominoski
- Department of Biological Sciences, Florida International University, Miami, Florida, United States
| | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Texas, USA
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5
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Rippel TM, Tomasula J, Murphy SM, Wimp GM. Global change in marine coastal habitats impacts insect populations and communities. CURRENT OPINION IN INSECT SCIENCE 2021; 47:1-6. [PMID: 33610775 DOI: 10.1016/j.cois.2021.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/07/2021] [Accepted: 02/10/2021] [Indexed: 06/12/2023]
Abstract
Salt marsh and mangrove coastal ecosystems provide critical ecosystem services, but are being lost at an alarming rate. Insect communities in these ecosystems are threatened by human impacts, including sea level rise, habitat loss, external inputs including nutrients, metals, and hydrocarbons, as well as weather events, such as hurricanes. While some disturbances are felt throughout the food web (e.g. hurricanes), others are mediated by impacts on the dominant plants (e.g. nutrient subsidies). The impacts of these disturbances on insects/spiders and their rate of recovery is dependent on trophic level, life history, and diet breadth. While we understand impacts of single disturbances relatively well, we have very little understanding of how multiple disturbances interact to affect insect communities.
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Affiliation(s)
- Tyler M Rippel
- Department of Biology, Georgetown University, 3700 O Street NW, Washington, D.C., USA.
| | - Jewel Tomasula
- Department of Biology, Georgetown University, 3700 O Street NW, Washington, D.C., USA
| | - Shannon M Murphy
- Department of Biology, University of Denver, 2190 E. Iliff Ave, Denver, CO, USA
| | - Gina M Wimp
- Department of Biology, Georgetown University, 3700 O Street NW, Washington, D.C., USA
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6
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Wimp GM, Murphy SM. Disentangling the effects of primary productivity and host plant traits on arthropod communities. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gina M. Wimp
- Department of Biology Georgetown University Washington DC USA
| | - Shannon M. Murphy
- Department of Biological Sciences University of Denver Denver CO USA
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7
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Lu X, Zhao X, Tachibana T, Uchida K, Sasaki T, Bai Y. Plant quantity and quality regulate the diversity of arthropod communities in a semi‐arid grassland. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13742] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoming Lu
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
| | - Xuezhen Zhao
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
- College of Lifesciences University of Chinese Academy of Sciences Beijing China
| | - Taiki Tachibana
- Graduate School of Environment and Information Sciences Yokohama National University Hodogaya Yokohama Japan
| | - Kei Uchida
- Institute for Sustainable Agro‐ecosystem Services The University of Tokyo Nishi‐Tokyo Japan
| | - Takehiro Sasaki
- Graduate School of Environment and Information Sciences Yokohama National University Hodogaya Yokohama Japan
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
- College of Resources and Environment University of Chinese Academy of Sciences Beijing China
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8
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Wimp GM, Lewis D, Murphy SM. Prey identity but not prey quality affects spider performance. CURRENT RESEARCH IN INSECT SCIENCE 2021; 1:100013. [PMID: 36003602 PMCID: PMC9387502 DOI: 10.1016/j.cris.2021.100013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 12/01/2022]
Abstract
Prey identity affected the survival and body mass of a generalist spider predator. Trophic level of the prey did not affect spider survival and body mass. Prey identity and cordgrass quality had an interactive effect on spider body mass. Greater spider body mass led to greater egg production. In a literature review, female spider fitness increased with greater body size.
Increasing host plant quality affects higher trophic level predators, but whether such changes are simply a result of prey density or are also affected by changes in prey quality remain uncertain. Moreover, whether changes in prey quality affect measures of predator performance is understudied. Using a combination of field and greenhouse mesocosm experiments, we demonstrate that the survival and body size of a hunting spider (Pardosa littoralis Araneae: Lycosidae) is affected more by prey species identity than the trophic level of the prey. Furthermore, increasing host plant quality does not necessarily propagate through the food web by altering prey quality. While changes in plant quality affected spider body mass, they did so in opposite ways for spiders feeding on Prokelisia (Hemiptera: Delphacodes) herbivores relative to Tytthus (Hemiptera: Miridae) egg predators, and had no impact on spider body mass for two additional species of intraguild prey. These changes in body mass were important because greater body mass increased spider egg production. To examine the generality of this pattern, we reviewed the literature and found a consistent positive relationship between female body size and egg production for Pardosa species, indicating that body size is a reliable proxy for fitness. While many studies emphasize the importance of nitrogen to arthropod diets, this focus may be driven largely by our understanding of herbivore diets rather than predator diets. Thus, the positive impact of host plant quality on higher trophic level predators appears to be driven more by altering prey composition, density, and availability rather than simply providing predators with more nutritious prey.
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Affiliation(s)
- Gina M. Wimp
- Department of Biology, Georgetown University, Washington, DC, USA
- Corresponding author.
| | - Danny Lewis
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Shannon M. Murphy
- Department of Biological Sciences, University of Denver, Denver, CO, USA
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9
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Reihart RW, Angelos KP, Gawkins KM, Hurst SE, Montelongo DC, Laws AN, Pennings SC, Prather CM. Crazy ants craving calcium: macronutrients and micronutrients can limit and stress an invaded grassland brown food web. Ecology 2020; 102:e03263. [PMID: 33314072 DOI: 10.1002/ecy.3263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/12/2020] [Accepted: 11/24/2020] [Indexed: 11/12/2022]
Abstract
Nitrogen and phosphorus are thought to be the most important limiting nutrients in most terrestrial ecosystems, but little is known about how other elements may limit the abundance of arthropods. We utilized a fully factorial fertilization experiment that manipulated macronutrients (N and P, together) and micronutrients (calcium, sodium, potassium, separately), in large 30 × 30 m plots and sampled litter arthropods via pitfall trapping to determine the nutrients that limit this group. An invasive ant, Nylanderia fulva, numerically dominated the community and increased in abundance 13% in plots fertilized by Ca. Detritivores were not limited by any nutrient combination, but macronutrients increased predator abundance 43%. We also found that some combinations of macronutrients and micronutrients had toxic or stressful effects on the arthropod community: detritivores decreased in abundance 23% with the combination of macronutrients, Ca, and K, and 22% with macronutrients and K; and N. fulva decreased in abundance 24% in plots fertilized by K and 45% in plots fertilized by the combination of Na and K. Our work supports growing evidence that micronutrients, especially Ca and K, may be important in structuring grassland arthropod communities, and suggests that micronutrients may affect whether or not invasive ants reach numerical dominance.
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Affiliation(s)
- Ryan W Reihart
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, USA
| | | | - Kaitlin M Gawkins
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, USA
| | - Shania E Hurst
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, USA
| | - Denise C Montelongo
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204, USA
| | - Angela N Laws
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204, USA
| | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204, USA
| | - Chelse M Prather
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, USA.,Department of Biology, Radford, Virginia, 46556, USA
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10
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Reis A, Barros F. Tropical saltmarshes are important to juvenile fiddler crabs but not as refuges from large predators or high temperatures. MARINE ENVIRONMENTAL RESEARCH 2020; 161:105133. [PMID: 32911252 DOI: 10.1016/j.marenvres.2020.105133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 07/27/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Tropical saltmarshes' role as a refuge for macrofauna is poorly known. We tested the hypotheses that: i) there is an increase in abundance of early life-stages of fiddler crabs associated with an increase in vegetation density (thermal and/or predation refuge) and ii) predation are lower within saltmarsh vegetation. The abundance of early life-stages increased with both vegetation density and temperature. Megalopa and juveniles might be adapted or benefit from high temperatures found on tropical saltmarshes and thus do not need protection from it. Predation was higher in saltmarshes than in nearby non-vegetated areas, thus tropical saltmarshes can not be considered a refuge from relatively large predators for juveniles of fiddler crabs. Although not offering refuge against temperature and predation, tropical saltmarshes are important habitats for the recruitment of early life-stages of fiddler crabs. Future studies should consider the evaluation of tropical saltmarsh hydrodynamics in the settlement and permanence of juveniles.
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Affiliation(s)
- Alice Reis
- Laboratório de Ecologia Bentônica, Instituto de Biologia & CIENAM, Universidade Federal da Bahia, Rua Barão de Geremoabo, s/n, Campus de Ondina, Salvador, Bahia, 40170-115, Brazil; Instituto Nacional de Ciência e Tecnologia, Estudos Interdisciplinares e Transdisciplinares em Ecologia e Evolução (INCT IN-TREE), Salvador, Bahia, Brazil.
| | - Francisco Barros
- Instituto Nacional de Ciência e Tecnologia, Estudos Interdisciplinares e Transdisciplinares em Ecologia e Evolução (INCT IN-TREE), Salvador, Bahia, Brazil
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11
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van Schalkwyk J, Pryke JS, Samways MJ, Gaigher R. Spillover of terrestrial arthropod species and beta diversity in perennial crops relative to spatial scale of land‐use intensity. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13638] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julia van Schalkwyk
- Department of Conservation Ecology and Entomology Stellenbosch University Matieland South Africa
| | - James S. Pryke
- Department of Conservation Ecology and Entomology Stellenbosch University Matieland South Africa
| | - Michael J. Samways
- Department of Conservation Ecology and Entomology Stellenbosch University Matieland South Africa
| | - René Gaigher
- Department of Conservation Ecology and Entomology Stellenbosch University Matieland South Africa
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12
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Diez F, Coscarón MDC. Roles of the environment, vegetation and spatial structure in the species composition of the Heteroptera community. SYST BIODIVERS 2020. [DOI: 10.1080/14772000.2020.1737844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Fernando Diez
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa CONICET, Uruguay 151, Santa Rosa, La Pampa, L6300CLB, Argentina
| | - MaríA Del Carmen Coscarón
- Facultad de Ciencias Naturales y Museo, División Entomología, Universidad Nacional de La Plata CONICET, Paseo del Bosque s/n 1900, La Plata, Buenos Aires, Argentina
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13
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Wimp GM, Lewis D, Murphy SM. Impacts of Nutrient Subsidies on Salt Marsh Arthropod Food Webs: A Latitudinal Survey. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00350] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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Montagano L, Leroux SJ, Giroux M, Lecomte N. The strength of ecological subsidies across ecosystems: a latitudinal gradient of direct and indirect impacts on food webs. Ecol Lett 2018; 22:265-274. [DOI: 10.1111/ele.13185] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/06/2018] [Accepted: 10/23/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Laurent Montagano
- Department of Biology Université de Moncton Moncton New BrunswickE1A 3E9 Canada
- Canada Research Chair in Polar and Boreal Ecology and Centre d’études nordiques Université de Moncton Moncton New Brunswick E1A 3E9 Canada
| | - Shawn J. Leroux
- Department of Biology Memorial University St‐John's, Newfoundland and LabradorA1B 3X9 Canada
| | - Marie‐Andrée Giroux
- K.‐C.‐Irving Chair in Environmental Sciences and Sustainable Development Université de Moncton Moncton New BrunswickE1A 3E9 Canada
| | - Nicolas Lecomte
- Department of Biology Université de Moncton Moncton New BrunswickE1A 3E9 Canada
- Canada Research Chair in Polar and Boreal Ecology and Centre d’études nordiques Université de Moncton Moncton New Brunswick E1A 3E9 Canada
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15
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Prather CM, Laws AN, Cuellar JF, Reihart RW, Gawkins KM, Pennings SC. Seeking salt: herbivorous prairie insects can be co-limited by macronutrients and sodium. Ecol Lett 2018; 21:1467-1476. [PMID: 30039540 DOI: 10.1111/ele.13127] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/23/2018] [Accepted: 06/08/2018] [Indexed: 11/28/2022]
Abstract
The canonical factors typically thought to determine herbivore community structure often explain only a small fraction of the variation in herbivore abundance and diversity. We tested how macronutrients and relatively understudied micronutrients interacted to influence the structure of insect herbivore (orthopteran) communities. We conducted a factorial fertilisation experiment manipulating macronutrients (N and P, added together) and micronutrients (Ca, Na and K) in large plots (30 × 30 m2 ) in a Texas coastal prairie. Although no single or combination of micronutrients affected herbivore communities in the absence of additional macronutrients, macronutrients and sodium added together increased herbivore abundance by 60%, richness by 15% and diversity by 20%. These results represent the first large-scale manipulation of single micronutrients and macronutrients in concert, and revealed an herbivore community co-limited by macronutrients and Na. Our work supports an emerging paradigm that Na may be important in limiting herbivore communities.
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Affiliation(s)
- Chelse M Prather
- Department of Biology, Radford University, Radford, VA, 46556, USA.,Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Angela N Laws
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA.,The Xerces Society, Sacramento, CA, 95814, USA
| | - Juan F Cuellar
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA
| | - Ryan W Reihart
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | | | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA
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16
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Liu Y, Ma G, Zan Z, Chen A, Miao Y, Wang D, Miao R. Effects of nitrogen addition and mowing on rodent damage in an Inner Mongolian steppe. Ecol Evol 2018; 8:3919-3926. [PMID: 29721268 PMCID: PMC5916279 DOI: 10.1002/ece3.3949] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/27/2018] [Accepted: 01/30/2018] [Indexed: 11/28/2022] Open
Abstract
Rodent damage is a serious threat to sustainable management of grassland. The effects of nitrogen (N) deposition and grassland management on rodent damage have been scarcely studied. Here, we reported the effects of 2 years of N addition and mowing on burrow density and damage area of Citellus dauricus in a semiarid steppe in Inner Mongolia. N addition significantly aggravated, while mowing alleviated rodent damage in the grassland under study. Burrow density and damage area increased 2.8‐fold and 4.7‐fold, in N addition plots compared to the ambient N addition treatment, respectively. Conversely, mowing decreased burrow density and damage area by 75.9% and 14.5%, respectively, compared to no mowing plots. Observed changes in rodent damage were mainly due to variations in plant community cover, height, and aboveground net primary productivity. Our findings demonstrate that N addition and mowing can affect the rodent density and activity in grassland, suggesting that the effects of a changing atmospheric composition and land use on rodent damage must be considered in order to achieve better grassland management.
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Affiliation(s)
- Yinzhan Liu
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Gaigai Ma
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Zhiman Zan
- Agricultural Schools Henan University of Science and Technology Luoyang China
| | - Anqun Chen
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Yuan Miao
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Dong Wang
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Renhui Miao
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
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17
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Bam W, Hooper-Bui LM, Strecker RM, Adhikari PL, Overton EB. Coupled effects of oil spill and hurricane on saltmarsh terrestrial arthropods. PLoS One 2018; 13:e0194941. [PMID: 29641552 PMCID: PMC5895010 DOI: 10.1371/journal.pone.0194941] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/13/2018] [Indexed: 11/21/2022] Open
Abstract
Terrestrial arthropods play an important role in saltmarsh ecosystems, mainly affecting the saltmarsh’s primary production as the main consumers of terrestrial primary production and decomposition. Some of these arthropods, including selected insects and spiders, can be used as ecological indicators of overall marsh environmental health, as they are differentially sensitive to ecological stressors, such as land loss, erosion, oil spills, and tropical storms. In the present study, we used terrestrial arthropods collected from seven (three lightly-oiled, four heavily-oiled) sites in Barataria Bay and from three unoiled reference sites in Delacroix, Louisiana, to determine the impacts of the distribution and re-distribution of Deepwater Horizon (DWH) oil on these saltmarsh ecosystems. A total of 9,476 and 12,256 insects were collected in 2013 and 2014, respectively. The results show that the terrestrial arthropods were negatively affected by the re-distribution of DWH oil by Hurricane Isaac in 2012, although the level of impacts varied among the arthropod groups. Moreover, the mean diversity index was higher (>1.5) in 2014 than in 2013 (<1.5) for all sites, suggesting a recovery trajectory of the saltmarsh arthropod population. The higher taxonomic richness observed in the reference sites compared to the oiled sites for both years also indicated long-term impacts of DWH oil to the saltmarsh arthropod community. Whereas a slow recovery of certain terrestrial arthropods was observed, long-term monitoring of arthropod communities would help better understand the recovery and succession of the marsh ecosystems.
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Affiliation(s)
- Wokil Bam
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, United States of America
- * E-mail:
| | - Linda M. Hooper-Bui
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, United States of America
| | - Rachel M. Strecker
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, United States of America
| | - Puspa L. Adhikari
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, United States of America
| | - Edward B. Overton
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, United States of America
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18
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Asmus A, Koltz A, McLaren J, Shaver GR, Gough L. Long-term nutrient addition alters arthropod community composition but does not increase total biomass or abundance. OIKOS 2017. [DOI: 10.1111/oik.04398] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Ashley Asmus
- Dept of Ecology; Evolution and Behavior, Univ. of Minnesota; St. Paul MN 55108 USA
| | - Amanda Koltz
- Dept of Biology; Washington Univ. in Saint Louis; St. Louis MO USA
| | - Jennie McLaren
- Dept of Biological Sciences; Univ. of Texas at El Paso; El Paso TX USA
| | - Gaius R. Shaver
- The Ecosystems Center, Marine Biological Laboratory; Woods Hole MA USA
| | - Laura Gough
- Dept of Ecology; Evolution and Behavior, Univ. of Minnesota; St. Paul MN 55108 USA
- Dept of Biological Sciences; Towson Univ.; Towson MD USA
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19
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Lind EM, La Pierre KJ, Seabloom EW, Alberti J, Iribarne O, Firn J, Gruner DS, Kay AD, Pascal J, Wright JP, Yang L, Borer ET. Increased grassland arthropod production with mammalian herbivory and eutrophication: a test of mediation pathways. Ecology 2017; 98:3022-3033. [PMID: 28940315 DOI: 10.1002/ecy.2029] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/28/2017] [Accepted: 08/31/2017] [Indexed: 11/07/2022]
Abstract
Increases in nutrient availability and alterations to mammalian herbivore communities are a hallmark of the Anthropocene, with consequences for the primary producer communities in many ecosystems. While progress has advanced understanding of plant community responses to these perturbations, the consequences for energy flow to higher trophic levels in the form of secondary production are less well understood. We quantified arthropod biomass after manipulating soil nutrient availability and wild mammalian herbivory, using identical methods across 13 temperate grasslands. Of experimental increases in nitrogen, phosphorus, and potassium, only treatments including nitrogen resulted in significantly increased arthropod biomass. Wild mammalian herbivore removal had a marginal, negative effect on arthropod biomass, with no interaction with nutrient availability. Path analysis including all sites implicated nutrient content of the primary producers as a driver of increased arthropod mean size, which we confirmed using 10 sites for which we had foliar nutrient data. Plant biomass and physical structure mediated the increase in arthropod abundance, while the nitrogen treatments accounted for additional variation not explained by our measured plant variables. The mean size of arthropod individuals was 2.5 times more influential on the plot-level total arthropod biomass than was the number of individuals. The eutrophication of grasslands through human activity, especially nitrogen deposition, thus may contribute to higher production of arthropod consumers through increases in nutrient availability across trophic levels.
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Affiliation(s)
- Eric M Lind
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, 55108, USA
| | - Kimberly J La Pierre
- Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, USA
| | - Eric W Seabloom
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, 55108, USA
| | - Juan Alberti
- Instituto de Investigaciones Marinas y Costeras (UNMDP-CONICET), B7602GSD Mar del Plata, Buenos Aires, Argentina
| | - Oscar Iribarne
- Instituto de Investigaciones Marinas y Costeras (UNMDP-CONICET), B7602GSD Mar del Plata, Buenos Aires, Argentina
| | - Jennifer Firn
- Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | | | - Adam D Kay
- University of St. Thomas, St Paul, Minnesota, 55105, USA
| | - Jesus Pascal
- Instituto de Investigaciones Marinas y Costeras (UNMDP-CONICET), B7602GSD Mar del Plata, Buenos Aires, Argentina
| | | | - Louie Yang
- University of California, Davis, Davis, California, 95616, USA
| | - Elizabeth T Borer
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, 55108, USA
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20
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Vidal MC, Murphy SM. Bottom‐up vs. top‐down effects on terrestrial insect herbivores: a meta‐analysis. Ecol Lett 2017; 21:138-150. [DOI: 10.1111/ele.12874] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/03/2017] [Accepted: 10/04/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Mayra C. Vidal
- Department of Biological Sciences University of Denver Denver CO USA
| | - Shannon M. Murphy
- Department of Biological Sciences University of Denver Denver CO USA
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21
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Wyckhuys KAG, Graziosi I, Burra DD, Walter AJ. Phytoplasma infection of a tropical root crop triggers bottom-up cascades by favoring generalist over specialist herbivores. PLoS One 2017; 12:e0182766. [PMID: 28813469 PMCID: PMC5559091 DOI: 10.1371/journal.pone.0182766] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 07/24/2017] [Indexed: 01/14/2023] Open
Abstract
Global interest on plant-microbe-insect interactions is rapidly growing, revealing the multiple ways in which microorganisms mediate plant-herbivore interactions. Phytopathogens regularly alter whole repertoires of plant phenotypic traits, and bring about shifts in key chemical or morphological characteristics of plant hosts. Pathogens can also cause cascading effects on higher trophic levels, and eventually shape entire plant-associated arthropod communities. We tested the hypothesis that a Candidatus Phytoplasma causing cassava witches' broom (CWB) on cassava (Manihot esculenta Grantz) is altering species composition of invasive herbivores and their associated parasitic hymenopterans. We conducted observational studies in cassava fields in eastern Cambodia to assess the effect of CWB infection on abundance of specialist and generalist mealybugs (Homoptera: Pseudococcidae), and associated primary and hyper-parasitoid species. CWB infection positively affects overall mealybug abundance and species richness at a plant- and field-level, and disproportionately favors a generalist mealybug over a specialist feeder. CWB phytoplasma infection led to increased parasitoid richness and diversity, with richness of 'comparative' specialist taxa being the most significantly affected. Parasitism rate did not differ among infected and uninfected plants, and mealybug host suppression was not impacted. CWB phytoplasma modifies host plant quality for sap-feeding homopterans, differentially affects success rates of two invasive species, and generates niche opportunities for higher trophic orders. By doing so, a Candidatus phytoplasma affects broader food web structure and functioning, and assumes the role of an ecosystem engineer. Our work unveils key facets of phytoplasma ecology, and sheds light upon complex multi-trophic interactions mediated by an emerging phytopathogen. These findings have further implications for invasion ecology and management.
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Affiliation(s)
- Kris A. G. Wyckhuys
- International Center for Tropical Agriculture (CIAT) Asia Regional Office, Hanoi, Vietnam
- * E-mail:
| | - Ignazio Graziosi
- University of Kentucky, Lexington, Kentucky, United States of America
| | - Dharani Dhar Burra
- International Center for Tropical Agriculture (CIAT) Asia Regional Office, Hanoi, Vietnam
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22
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Olin JA, Bergeon Burns CM, Woltmann S, Taylor SS, Stouffer PC, Bam W, Hooper-Bui L, Turner RE. Seaside Sparrows reveal contrasting food web responses to large-scale stressors in coastal Louisiana saltmarshes. Ecosphere 2017. [DOI: 10.1002/ecs2.1878] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Jill A. Olin
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - Christine M. Bergeon Burns
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Stefan Woltmann
- Department of Biology and Center of Excellence for Field Biology; Austin Peay State University; Clarksville Tennessee 37044 USA
| | - Sabrina S. Taylor
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Philip C. Stouffer
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Wokil Bam
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - Linda Hooper-Bui
- Department of Environmental Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - R. Eugene Turner
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
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23
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Stephan JG, Stenberg JA, Björkman C. Consumptive and nonconsumptive effect ratios depend on interaction between plant quality and hunting behavior of omnivorous predators. Ecol Evol 2017; 7:2327-2339. [PMID: 28405296 PMCID: PMC5383501 DOI: 10.1002/ece3.2828] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/30/2016] [Accepted: 01/03/2017] [Indexed: 12/05/2022] Open
Abstract
Predators not only consume prey but exert nonconsumptive effects in form of scaring, consequently disturbing feeding or reproduction. However, how alternative food sources and hunting mode interactively affect consumptive and nonconsumptive effects with implications for prey fitness have not been addressed, impending functional understanding of such tritrophic interactions. With a herbivorous beetle, two omnivorous predatory bugs (plant sap as alternative food, contrasting hunting modes), and four willow genotypes (contrasting suitability for beetle/omnivore), we investigated direct and indirect effects of plant quality on the beetles key reproductive traits (oviposition rate, clutch size). Using combinations of either or both omnivores on different plant genotypes, we calculated the contribution of consumptive (eggs predated) and nonconsumptive (fewer eggs laid) effect on beetle fitness, including a prey density‐independent measure (c:nc ratio). We found that larger clutches increase egg survival in presence of the omnivore not immediately consuming all eggs. However, rather than lowering mean, the beetles generally responded with a frequency shift toward smaller clutches. However, female beetles decreased mean and changed clutch size frequency with decreasing plant quality, therefore reducing intraspecific exploitative competition among larvae. More importantly, variation in host plant quality (to omnivore) led to nonconsumptive effects between one‐third and twice as strong as the consumptive effects. Increased egg consumption on plants less suitable to the omnivore may therefore be accompanied by less searching and disturbing the beetle, representing a “cost” to the indirect plant defense in the form of a lower nonconsumptive effect. Many predators are omnivores and altering c:nc ratios (with egg retention as the most direct link to prey fitness) via plant quality and hunting behavior should be fundamental to advance ecological theory and applications. Furthermore, exploring modulation of fitness traits by bottom‐up and top‐down effects will help to explain how and why species aggregate.
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Affiliation(s)
- Jörg G. Stephan
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Johan A. Stenberg
- Department of Plant Protection BiologySwedish University of Agricultural SciencesAlnarpSweden
| | - Christer Björkman
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
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24
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Clare DS, Spencer M, Robinson LA, Frid CLJ. Explaining ecological shifts: the roles of temperature and primary production in the long-term dynamics of benthic faunal composition. OIKOS 2017. [DOI: 10.1111/oik.03661] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- David S. Clare
- School of Environmental Sciences, Univ. of Liverpool, Brownlow Street, Liverpool; L69 3GP UK
| | - Matthew Spencer
- School of Environmental Sciences, Univ. of Liverpool, Brownlow Street, Liverpool; L69 3GP UK
| | - Leonie A. Robinson
- School of Environmental Sciences, Univ. of Liverpool, Brownlow Street, Liverpool; L69 3GP UK
| | - Christopher L. J. Frid
- School of Environmental Sciences, Univ. of Liverpool, Brownlow Street, Liverpool; L69 3GP UK
- Griffith School of Environment, Griffith Univ.; Southport QLD Australia
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25
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Burrowing seabird effects on invertebrate communities in soil and litter are dominated by ecosystem engineering rather than nutrient addition. Oecologia 2015; 180:217-30. [PMID: 26410032 DOI: 10.1007/s00442-015-3437-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/30/2015] [Indexed: 10/23/2022]
Abstract
Vertebrate consumers can be important drivers of the structure and functioning of ecosystems, including the soil and litter invertebrate communities that drive many ecosystem processes. Burrowing seabirds, as prevalent vertebrate consumers, have the potential to impact consumptive effects via adding marine nutrients to soil (i.e. resource subsidies) and non-consumptive effects via soil disturbance associated with excavating burrows (i.e. ecosystem engineering). However, the exact mechanisms by which they influence invertebrates are poorly understood. We examined how soil chemistry and plant and invertebrate communities changed across a gradient of seabird burrow density on two islands in northern New Zealand. Increasing seabird burrow density was associated with increased soil nutrient availability and changes in plant community structure and the abundance of nearly all the measured invertebrate groups. Increasing seabird densities had a negative effect on invertebrates that were strongly influenced by soil-surface litter, a positive effect on fungal-feeding invertebrates, and variable effects on invertebrate groups with diverse feeding strategies. Gastropoda and Araneae species richness and composition were also influenced by seabird activity. Generalized multilevel path analysis revealed that invertebrate responses were strongly driven by seabird engineering effects, via increased soil disturbance, reduced soil-surface litter, and changes in trophic interactions. Almost no significant effects of resource subsidies were detected. Our results show that seabirds, and in particular their non-consumptive effects, were significant drivers of invertebrate food web structure. Reductions in seabird populations, due to predation and human activity, may therefore have far-reaching consequences for the functioning of these ecosystems.
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26
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Patterns of Trophic-level Diversity Associated with Herbaceous Dune Vegetation Across a Primary Successional Gradient. AMERICAN MIDLAND NATURALIST 2015. [DOI: 10.1674/amid-173-02-177-190.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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Pennings SC, McCall BD, Hooper-Bui L. Effects of Oil Spills on Terrestrial Arthropods in Coastal Wetlands. Bioscience 2014. [DOI: 10.1093/biosci/biu118] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Plant production and alternate prey channels impact the abundance of top predators. Oecologia 2013; 173:331-41. [PMID: 23604861 DOI: 10.1007/s00442-013-2618-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 02/05/2013] [Indexed: 10/26/2022]
Abstract
While numerous studies have examined the effects of increased primary production on higher trophic levels, most studies have focused primarily on the grazing food web and have not considered the importance of alternate prey channels. This has happened despite the fact that fertilization not only increases grazing herbivore abundance, but other types of consumers such as detritivores that serve as alternate prey for generalist predators. Alternate prey channels can sustain generalist predators at times when prey abundance in the grazing food web is low, thus increasing predator densities and the potential for trophic cascades. Using arthropod data from a fertilization experiment, we constructed a hierarchical Bayesian model to examine the direct and indirect effects of plant production and alternate prey channels on predators in a salt marsh. We found that increased plant production positively affected the density of top predators via effects on lower trophic level herbivores and mesopredators. Additionally, while the abundance of algivores and detritivores positively affected mesopredators and top predators, respectively, the effects of alternate prey were relatively weak. Because previous studies in the same system have found that mesopredators and top predators rely on alternate prey such as algivores and detritivores, future studies should examine whether fertilization shifts patterns of prey use by predators from alternate channels to the grazing channel. Finally, the hierarchical Bayesian model used in this study provided a useful method for exploring trophic relationships in the salt marsh food web, especially where causal relationships among trophic groups were unknown.
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30
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Murphy SM, Wimp GM, Lewis D, Denno RF. Nutrient presses and pulses differentially impact plants, herbivores, detritivores and their natural enemies. PLoS One 2012; 7:e43929. [PMID: 22952814 PMCID: PMC3429447 DOI: 10.1371/journal.pone.0043929] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 07/27/2012] [Indexed: 11/18/2022] Open
Abstract
Anthropogenic nutrient inputs into native ecosystems cause fluctuations in resources that normally limit plant growth, which has important consequences for associated food webs. Such inputs from agricultural and urban habitats into nearby natural systems are increasing globally and can be highly variable, spanning the range from sporadic to continuous. Despite the global increase in anthropogenically-derived nutrient inputs into native ecosystems, the consequences of variation in subsidy duration on native plants and their associated food webs are poorly known. Specifically, while some studies have examined the effects of nutrient subsidies on native ecosystems for a single year (a nutrient pulse), repeated introductions of nutrients across multiple years (a nutrient press) better reflect the persistent nature of anthropogenic nutrient enrichment. We therefore contrasted the effects of a one-year nutrient pulse with a four-year nutrient press on arthropod consumers in two salt marshes. Salt marshes represent an ideal system to address the differential impacts of nutrient pulses and presses on ecosystem and community dynamics because human development and other anthropogenic activities lead to recurrent introductions of nutrients into these natural systems. We found that plant biomass and %N as well as arthropod density fell after the nutrient pulse ended but remained elevated throughout the nutrient press. Notably, higher trophic levels responded more strongly than lower trophic levels to fertilization, and the predator/prey ratio increased each year of the nutrient press, demonstrating that food web responses to anthropogenic nutrient enrichment can take years to fully manifest themselves. Vegetation at the two marshes also exhibited an apparent tradeoff between increasing %N and biomass in response to fertilization. Our research emphasizes the need for long-term, spatially diverse studies of nutrient enrichment in order to understand how variation in the duration of anthropogenic nutrient subsidies affects native ecosystems.
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Affiliation(s)
- Shannon M Murphy
- Department of Biological Sciences, University of Denver, Denver, Colorado, United States of America.
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31
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McCall BD, Pennings SC. Geographic variation in salt marsh structure and function. Oecologia 2012; 170:777-87. [DOI: 10.1007/s00442-012-2352-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 04/25/2012] [Indexed: 11/29/2022]
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32
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Disturbance and recovery of salt marsh arthropod communities following BP Deepwater Horizon oil spill. PLoS One 2012; 7:e32735. [PMID: 22412916 PMCID: PMC3296729 DOI: 10.1371/journal.pone.0032735] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/03/2012] [Indexed: 11/19/2022] Open
Abstract
Oil spills represent a major environmental threat to coastal wetlands, which provide a variety of critical ecosystem services to humanity. The U.S. Gulf of Mexico is a hub of oil and gas exploration activities that historically have impacted intertidal habitats such as salt marsh. Following the BP Deepwater Horizon oil spill, we sampled the terrestrial arthropod community and marine invertebrates found in stands of Spartina alterniflora, the most abundant plant in coastal salt marshes. Sampling occurred in 2010 as oil was washing ashore and a year later in 2011. In 2010, intertidal crabs and terrestrial arthropods (insects and spiders) were suppressed by oil exposure even in seemingly unaffected stands of plants; however, Littoraria snails were unaffected. One year later, crab and arthropods had largely recovered. Our work is the first attempt that we know of assessing vulnerability of the salt marsh arthropod community to oil exposure, and it suggests that arthropods are both quite vulnerable to oil exposure and quite resilient, able to recover from exposure within a year if host plants remain healthy.
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Wimp GM, Murphy SM, Lewis D, Ries L. Do edge responses cascade up or down a multi-trophic food web? Ecol Lett 2011; 14:863-70. [DOI: 10.1111/j.1461-0248.2011.01656.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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34
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The Humpbacked Species Richness-Curve: A Contingent Rule for Community Ecology. INTERNATIONAL JOURNAL OF ECOLOGY 2011. [DOI: 10.1155/2011/868426] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Functional relationships involving species richness may be unimodal, monotonically increasing, monotonically decreasing, bimodal, multimodal, U-shaped, or with no discernable pattern. The unimodal relationships are the most interesting because they suggest dynamic, nonequilibrium community processes. For that reason, they are also contentious. In this paper, we provide a wide-ranging review of the literature on unimodal (humpbacked) species richness-relationships. Though not as widespread as previously thought, unimodal patterns of species richness are often associated with disturbance, predation and herbivory, productivity, spatial heterogeneity, environmental gradients, time, and latitude. These unimodal patterns are contingent on organism and environment; we examine unimodal species richness-curves involving plants, invertebrates, vertebrates, plankton, and microbes in marine, lacustrine, and terrestrial habitats. A goal of future research is to understand the contingent patterns and the complex, interacting processes that generate them.
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35
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Eubanks MD, Raupp MJ, Finke DL. Robert F. Denno (1945-2008): insect ecologist extraordinaire. ANNUAL REVIEW OF ENTOMOLOGY 2011; 56:273-292. [PMID: 20822445 DOI: 10.1146/annurev-ento-120709-144825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Robert F. Denno was widely recognized as one of the leading insect ecologists in the world. He made major contributions to the study of plant-insect interactions, dispersal, interspecific competition, predator-prey interactions, and food web dynamics. He was especially well known for his detailed and comprehensive study of the arthropods that inhabit salt marshes. Denno promoted a research approach that included detailed knowledge of the natural history of the study system, meticulous experiments that often pushed logistical possibilities, and a focus on important ecological questions of the day. He was an enthusiastic collaborator and excellent mentor who invested incredible amounts of time and energy in the training and placement of graduate students and postdoctoral associates. As a result, Denno's legacy will continue to shape the field of insect ecology for generations to come.
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Affiliation(s)
- Micky D Eubanks
- Department of Entomology, Texas A&M University, College Station, Texas 77843, USA.
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